The state's high-stakes exam was supposed to be one of the most stressful-and boring-days of the year at Campos Intermediate School.

No one expected it to become the most dangerous.

Just as testing is about to begin, the principal's voice crackles over the intercom, panicked and trembling:

"Lock Down Lights Off. Lock Down Lights Off."

Classrooms go dark. Doors are barricaded. An unknown voice begins taunting students and teachers over the intercom.

Trapped inside Room 203, teacher Kate Jespersen and her students are forced to confront not only the danger outside their classroom door, but also the fears, regrets, and wounds they have carried for years. As the lockdown stretches from minutes into hours, they discover that when faced with a life-or-death situation, what truly matters becomes impossible to ignore.

Meanwhile, the mysterious intruder forces students and teachers alike to endure his own disturbing series of "tests."

Some will discover courage they never knew they possessed.

Some will break.

Because those responsible for the lockdown chose this day for a reason.

And before the lights come back on, everyone will be tested.

Not everyone will pass.

The Breakfast Club meets Lord of the Flies in this gripping YA psychological thriller.